Ubisoft Says InGame Ads in Old Assassins Creed Titles Were Down to a Technical Error

Which has now been addressed.

Update: Ubisoft has responded to this situation with a statement to The Verge. "We have been made aware that some players encountered pop-up ads while playing certain Assassin’s Creed titles yesterday," it says. "This was the result of a technical error that we addressed as soon as we learned of the issue."

We suppose that's that, then.